Submission #693273

#	Time	Username	Problem	Language	Result	Execution time	Memory
693273		vuavisao	Paprike (COI18_paprike)	C++14	100 / 100	73 ms	38316 KiB

paprike

#include<bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#define ll long long
using namespace std;

const ll N = 1e6 + 10;

ll n, k;
ll a[N];
vector<ll> g[N];

ll cost[N];
ll res;

void dfs(ll u, ll p) {
    cost[u] = a[u];
    for(const auto& v : g[u]) {
        if(v == p) continue;
        dfs(v, u);
    }
    sort(g[u].begin(), g[u].end(), [&] (ll lhs, ll rhs) -> bool {
        return cost[lhs] < cost[rhs];
    });
    ll need = (ll) g[u].size();
    for(const auto& v : g[u]) {
        if(v == p) {
            -- need;
            continue;
        }
        if(cost[u] + cost[v] <= k) {
            cost[u] += cost[v];
            -- need;
        }
    }
    res += need;
}

int32_t main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    if (fopen("COI18_PAPRIKE.inp", "r")) {
        freopen("COI18_PAPRIKE.inp", "r", stdin);
        freopen("COI18_PAPRIKE.out", "w", stdout);
    }
    cin >> n >> k;
    for(ll i = 1; i <= n; ++ i) cin >> a[i];
    for(ll i = 2; i <= n; ++ i) {
        ll u, v; cin >> u >> v;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    dfs(1, 0);
    cout << res;
    return 0;
}

/// Code by vuavisao

Compilation message (stderr)

paprike.cpp: In function 'int32_t main()':
paprike.cpp:44:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   44 |         freopen("COI18_PAPRIKE.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
paprike.cpp:45:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   45 |         freopen("COI18_PAPRIKE.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 13 / 13
• Subtask 3: 27 / 27
• Subtask 4: 49 / 49